Liquid chromatography systems are an important tool to the analytical chemist for the separation and analysis of samples of interest. Often, after separation in the liquid chromatograph, the components require further analysis to confirm the identity of these components. This may be performed using a mass and/or ion mobility spectrometer. However, connecting liquid chromatography systems to mass and/or ion mobility spectrometers can be a difficult and time consuming task.
Tubing may be used to deliver eluent to an ion source, wherein the eluent from the liquid chromatography system is sprayed into the ion source chamber through a capillary. This can result in an awkward connection that requires dexterity and skill to assemble. Moreover, there is a risk of electric shock at the connection for the user assembling the instrument connection, especially if there is a leak. The connecting assembly can also be expensive.
Furthermore, the fitting of the liquid chromatography tube connection into an ion source can take a long time, resulting in inactivity of the instrument. Poor instrument performance may also occur if parts are omitted or poorly assembled. This can result in dead volumes, which may lead to poor reproducibility or poor performance of the instrument.
The Applicant's earlier application GB-2520389 addresses these and other problems by providing a probe assembly for delivering eluent to a mass spectrometer, wherein a joint between an electrically insulated liquid line and a conductive capillary is provided downstream of an attachment device that attaches the probe to the spectrometer. This means that the eluent is less likely to leak out of the spectrometer when the probe is attached. A conductive member is provided in order to supply a voltage from the attachment device, downstream beyond the insulated liquid line and to the conductive capillary. This enables a voltage to be supplied relatively easily from the mass spectrometer to the conductive capillary via the attachment device, even though the electrically insulated liquid line is interposed between the attachment device and the conductive capillary. The structure of the probe therefore enables the electrical connection to be made between the spectrometer and the conductive capillary relatively quickly and easily.
Notwithstanding the benefits associated with the probe assembly described in GB-2520389, the Applicants believe that there remains scope for further improvements to mass and/or ion mobility systems in which an atmospheric pressure ionisation probe is coupled with mass and/or ion mobility spectrometer.
It is therefore desired to provide improved apparatus for mass and/or ion mobility spectrometry.